FIG 5. Case 3: 48-year-old woman with meningocele.

A, Axial CT scan shows a sharply marginated, expansile left petrous apex mass (asterisk).

B, Coronal T1-weighted (350/10/2) MR image shows a cyst of CSF signal intensity extending inferiorly into the petrous apex (arrows).

C, Axial T2-weighted FSE (2800/90/1) MR image confirms that the expansile mass revealed on CT studies is a cyst with CSF signal intensity (asterisk) extending from Meckel's cave into the petrous apex.